Vignesh Subramanian ’24
Optic neuritis (ON) is a condition involving inflammation of the optic nerve that can cause its demyelination, or the destruction of the fatty tissue known as myelin that insulates and protects nerves. Although relatively rare, ON first manifests in young adulthood and can cause diminished visual acuity or blurriness, poor pupillary constriction, ophthalmalgia (eye pain), and the inability to see out of one eye. The condition is common among patients with multiple sclerosis (MS), a progressive neurodegenerative disease involving autoimmune demyelination, and is characterized as one of the disease’s first signs. However, the study of ON’s potential to cause lasting disability has been limited in clinical trials. To better understand the relationship between the prognosis of ON and MS symptoms, an international study explored the long-term outcomes of patients presenting with both disorders.
Researchers first sampled 1,317 patients from MSBase, a collaborative dataset of outcomes data in MS and related conditions. These patients were screened to ensure they met the inclusion criteria of having been diagnosed with clinically isolated syndrome (CIS) – one of four MS disease courses involving a first episode of neurological symptoms lasting 24 hours – and having exhibited ON onset. Patients were then administered either corticosteroids or MS disease-modifying therapies ranging from injectables to immunosuppressive agents. Expanded disability status scale (EDSS) assessments and visual function scores (VFS), which were also taken at baseline, quantified patients’ level of physical and visual disability and were compared to annualized relapse rates, sensitivity, and survival analyses, and Kurtzke’s functional scores. Patients with sustained EDSS/VFS progression or advancement to clinically definite MS (CDMS), a later stage of the disease, were noted.
Researchers found that in the presence of MS, disability accumulation in the visual domain tracked with that of all other functional systems for at least 15 years. However, while the majority of the CIS cohort went on to develop CDMS, a larger proportion of the cohort demonstrated improved neurological and visual function in VFS scores than in previous trials that lacked preventative immunomodulatory therapies. These results indicate that high potency, disease-modifying therapies could delay the onset of MS and reduce the risk of both CDMS conversion and sustained EDSS/VFS progression in CIS patients. Such findings are crucial in improving diagnostic measures, as they substantiate the case for including the optic nerve as an MRI lesion site in MS evaluation criteria and thus may allow earlier diagnosis of CIS and initiation of treatment.
 L. Balcer, et al., Long-term outcomes in patients presenting with optic neuritis: analyses of the MSBase registry. Journal of the Neurological Sciences 430, 1-10 (2021). doi: 10.1016/j.jns.2021.118067 Image retrieved from: https://commons.wikimedia.org/wiki/File:Optic-neuritis-in-the-right-eye.jpg